Regenerable immobilized aminosilane sorbents for carbon dioxide capture applications

Abstract

A method for the separation of carbon dioxide from ambient air and flue gases is provided wherein a phase separating moiety with a second moiety are simultaneously coupled and bonded onto an inert substrate to create a mixture which is subsequently contacted with flue gases or ambient air. The phase-separating moiety is an amine whereas the second moiety is an aminosilane, or a Group 4 propoxide such as titanium (IV) propoxide (tetrapropyl orthotitanate, C 12 H 28 O 4 Ti). The second moiety makes the phase-separating moiety insoluble in the pores of the inert substrate. The new sorbents have a high carbon dioxide loading capacity and considerable stability over hundreds of cycles. The synthesis method is readily scalable for commercial and industrial production.

The embodiment of the invention in which an exclusive property or privilege is claimed is defined as follows: 
     
       1. A method for the separation of carbon dioxide from fluid, the method comprising:
 (a) simultaneously coupling a phase-separating polymeric amine moiety with a stabilizing moiety and bonding them onto an inert substrate in a single step to create a mixture; and 
 (b) contacting the mixture with the fluid to remove carbon dioxide. 
 
     
     
       2. The method as recited in  claim 1  wherein the phase-separating moiety polymeric amine is selected from the group consisting of linear primary amines, linear secondary amines, linear tertiary amines, branched primary amines, branched secondary amines, branched tertiary amines and any combination thereof. 
     
     
       3. The method as recited in  claim 1  wherein the stabilizing moiety is a compound selected from the group consisting of organoalkoyoxysilanes, titanium (IV) propoxide, zirconium (IV) propoxide, and hafnium (IV) propoxide. 
     
     
       4. The method as recited in  claim 1  wherein the stabilizing moiety causes the phase-separating moiety to be water-insoluble in the pores of the inert substrate. 
     
     
       5. The method as recited in  claim 1  wherein the bonding is both chemical and physical. 
     
     
       6. The method as recited in  claim 1  wherein the fluid is derived from point sources or ambient atmospheres. 
     
     
       7. The method as recited in  claim 1  wherein the fluid contains a partial pressure of CO 2  from about 0 atmosphere (atm) to 1 atm. 
     
     
       8. The method as recited in  claim 1  wherein the CO 2  reacts with the phase-separating moiety. 
     
     
       9. The method as recited in  claim 1  wherein the coupled phase-separating moiety is regenerated by pressure swinging. 
     
     
       10. The method as recited in  claim 1  wherein the temperature range for operation is from about ambient temperature to about 100° C. 
     
     
       11. The method as recited in  claim 1  wherein the range of the total pressure for operation is from of about 1 atm to 40 atm.